1. Field of the Invention
The present invention relates generally to a device and method for supplying a sorbent, at one or more various desired supply points in a flue gas stream, to boilers, heaters, kilns, or other flue gas-, or combustion gas-, generating devices (e.g., those located at power plants, processing plants, etc.). In one embodiment, the device of the present invention that is designed to supply a sorbent comprises a series of coaxial pipes. In another embodiment, the device of the present invention that is designed to supply a sorbent comprises a mixing section with a plurality of distribution vanes contained in at least one mixing section.
2. Description of the Related Art
In the field of sorbent supply there have, to date, been three existing designs pertaining to the injection of sorbents into a gas stream. The first consists of an open pipe. This design allows for injection of sorbent at one particular point. Overall coverage is achieved by using lances of different lengths at several locations. The second consists of a pipe with a closed bottom and several holes along the axial length of the lance. The intent of this design is to inject sorbent at several locations simultaneously. This is not achievable as the sorbent particles typically bypass several of the holes and is largely injected at one elevation. Finally some designs incorporate a shaped surface at the outlet to aid in sorbent dispersion. These designs inject PAC at one location.
A review of publicly available information showed two existing designs pertaining to the distribution of powdered sorbent from a main feed pipe to several, separate distribution pipes. The first consists of a manifold with separate flanged connections. Computer modeling of this device showed that sorbent particles typically bypass several of the connections and largely are fed to a single connection. The second consists of a cylindrical device with multiple outlets. Computer modeling demonstrates this device can result in highly localized distribution. This device has a top inlet from the main feed pipe.
Given the above, a need exists for a device and method that provides sorbent to a gas stream in various design situations and which is reliable and controllable.